This invention relates to electronic data storage, content management and retrieval systems and more particularly to methods and apparatus for storing metadata describing multimedia data in a standardized format.
Digital multimedia is stored in a variety of formats that are very different from alphanumeric data. While textual information supports the concepts of alphabetical ordering, indexing, and searching, media data does not. Multimedia formats are typically designed to fulfill playback rather than manageability requirements. In order to add manageability, it is common to associate text-based descriptive xe2x80x9cmetadataxe2x80x9d or xe2x80x9cannotationsxe2x80x9d with the media content.
In some cases, annotations can be automatically extracted from the media. Examples include time-based samples of audio or video presentations, and reduced-sized thumbnail views of image data. Many popular media formats, such as QuickTime(trademark) from Apple Computer and Advanced Streaming Format (ASF) from Microsoft Corp., are designed to capture and store a user""s text descriptions as well as system annotations, and such metadata is generally added during media creation and editing. In addition, emerging standards such as Digital Versatile Disc (DVD) and MPEG-7 support even richer metadata which facilitates the design of automated media management solutions. However, there is no unified way of capturing and using this metadata in application programs. Instead, special-purpose routines must be written by the application programmer to handle each of the wide variety of metadata storage techniques used by different proprietary media formats.
The present invention may be employed to capture metadata stored in diverse proprietary formats, as well to capture user-generated metadata and metadata from other sources, and to transform the captured metadata into logical annotations stored in a standard format. The standardized metadata allows the described digital media to be more readily managed, indexed, and searched by application programs without special programming.
In the specific embodiment of the invention described below, a media-specific metadata extracting component is used to extract metadata already stored in the media file according to the file format specifications for that particular media type. A sample extraction program program is also executed to analyze the media file to generate additional information, such as time-based file samples, which characterize the content of the file. In addition, a further routine may be executed to acquire auxiliary data from one or more sources external to the media file being described, including such sources as the Internet or keyboarded descriptions entered by the user.
As contemplated by the invention, after the metadata describing the media file is obtained, it is combined to form a set of logical annotations to the file. If desired, the resulting logical annotations may be selectively organized into summary data which may be added to the original logical annotations. The resulting logical annotations are then placed in a standard data representation, preferably extended Markup Language (XML). These annotations may then be stored, along with the original media, in a database adapted for storing XML data. The metadata which is stored in the database in this fashion may then be accessed by application programs in standard ways to perform data management, search, retrieval and playback functions.
These and other objects, features and advantages of the present invention may be better understood by considering the following detailed description of the preferred embodiment of the invention. In the course of this description, reference will frequently be made to the attached drawings.